I've just done 70 620 today and passed with 892, it wasn't quite as straight forward as I was expecting! I did the 622 MCTS while it was in its beta phase so should get MCITP enterprise support now.
I'm planning on upgrading my MCSE in the next month and the path specifies the vista client exam, they're not likely to remove it due to an alternate OS coming out.
I say go for it! IF you need any tips on what I was tested with feel free to ask!
(Ps, anyone remember how you change your signiture?!)
A+,N+,S+,Security +,MCSE
70-270-passed
70-290-passed
70-291-passed
70-293-passed
70-294-passed
70-297-passed
70-298-pending
70-299-pending